Admittedly, you probably don’t replace your makeup as often as you should. It’s a huge pain and those Dior brow pencils don’t come cheap. So how often do you actually need to toss out your makeup and buy new products?

It really depends on the product. Different types of makeup have different shelf-lives. Most actually come with a jar symbol with a number signifying how many months you have until you should throw the product out. Of course, you should use common sense: if your mascara is crusty or your lipstick smells funny, it’s time to toss them.

As a general rule of thumb, foundation, concealer, lip liner and nail polish are all usually good for about a year. Liquid eyeliner stays good for about six months, and bronzer, blush, eye shadow, pencil eyeliner and lipstick stays good for about a year and a half. Makeup sponges should be thrown away after one month and mascara should be tossed after about three months.

If you can hardly remember what you had for dinner last night, let alone when you bought that lip liner, write the date on the product in sharpie as soon as you buy it.